A new paper claims to document a medical first: death by marijuana. Researchers at hospitals in Dusseldorf and Frankfurt performed full postmortem investigations on two men, ages 23 and 28, who were seemingly healthy prior to their deaths and ruled that marijuana exposure triggered fatal cardiovascular complications in both. The younger man seemed to have an underlying heart condition and the older had a history of substantial drug use, factors which may have altered the way their bodies reacted to pot. This finding was a "diagnosis by exclusion," meaning that the researchers came to their stunning conclusion via a process of elimination. That method has left the researchers open to criticism.

Dr. Murray Mittleman, director of cardiovascular epidemiology at Beth Israel Deaconess Medical Center, says that the paper's findings are speculative, but adds that other studies have suggested an increased risk (albeit fleeting) of heart attack after smoking marijuana. Still, it is difficult to determine whether marijuana itself is actually the catalyst or just the act of smoking.

"We don't really know if it's marijuana or if it's just something that is related inhaling plant combustion products," says Mittleman. In other words, smoking tobacco may lead to the same complications.

Without much to go on, Mittleman advises that people be mindful of the risks that have been associated with smoking pot, particularly if they are older and have heart disease. Still, research suggests that the medical benefits of marijuana normally outweigh the risks associated with its consumption.